Theodolite



Sept. 16 1924. 1,508,585

1 -1. WILD THEODOLITE Filed May 13 1921 2 Sheets-Sheet l H. WILD THEODQLITE Sept. 16 1924.

Filed May 13. 1921 2 Sheets-Sheet Fig.5

Patented Sept. 16, 1924.

UNITED STATES HEINRICH WILD, or HEERBRUGG, swiTzEnLAivn.

THEODOLITE.

, Application filed May 13, 1921. Serial No. 469,195.

To all whom it may concern.

Be it known that I, HEINRIQH l/VILD, a citizen of Switzerland, residing at Heerbrugg, Switzerland, have invented a new and useful Theodolite, of which the following is a specification.

This invention relates to certain new and useful improvements in a theodolite and it has for its primary object'to provide an improved optic structure in which in the field of view of a reading microscope two carrier.

closing prism casing having an upstanding, journal to receive the pivot 0 said casing, having a: compartment into which an annular glass body (2? is rigidly inserted. The,

- glassring (Z is the carrier of the horizontal opposite places of av divided circle are simultaneously so imaged that the two scaleimages run parallel to each other and touch each other along a boundaryjline.

The invention also resides in an improved mounting and arrangement ofprism systems with means for adjusting certain of them} to obtain proper displacement of the images.

A further object is to provide a branched or double disposition of the eye-lens system with an adjustable prism for directing the rays to either branch.

The invention further resldes 111 novel means for mounting and ELClJUStlIlg the plano-parallel prisms or glass plates by Figs. 3, 4 and 5 illustrate particulars of the instrument in section according to the corresponding lines of intersection of Fig. '2

whilst Fig. 6 reproduces the image presented in the field of view of the reading ocular.

an upper body 0, representing the telescope The lower body 7) forms aniina circle; the di'visionof the circle is etched on The instrument has in a well-known way a lower body 6, adjustable by three. screws a, in which there is rotatably sup ported by means of a conical, hollow. pivot 0* the outer, cylindrical surface cl ofthe ring and protected by a reflecting coat applied to the said surface 6Z Within the hollow space enclosed by the glass ring (Z there are ,585" A NT series;

two reflecting prisms e and two smaller re-f flecting prisms 6 cemented to; the same, i

which are immovably disposed in a joint casing 6 tightly'screwed to the, pivot c lVith the aid of a reflecting prisni e fixed, underneath the part b, an illuminating ray pencil coming from outside is transmitted through a' centralaperture 5 to the two prisms e and from here each halfof the said my pencilreachestwo opposite places of the surface d carrying the division of r the circle. Owing tothe reflecting coat ap plied to the said surface, the incident rays are reflected in an approximately radial direction and thereby the division of the circle appears dark on 'a light ground. The in clined surfaces, coinciding in the axis, of the two prisms e reflect the rays, reflected by the two places of the divided circle, with aslight, relative inclination into the hollow space of the pivot c where they first pene-f trate a common lens system f, embodying the ob ective ofthe reading microscope and are then transmitted in an approximately hori} zontal direction by a likewise common re-,

fleeting prism f The same device as described above for the horizontal circle is also provided 001'- respondingly for the circle of altitude. On

the telescope carrier 0 there is rotatably 'dis- J posed about an axis perpendicular to that of the pivot c a part 9, to which the 't'e'le-' In the drawing this is only shown by a boring provided for in thepart ,7. Directly beside the telescope the part is carried. out as a.

scope is assumed to be adapted.

universally closed easing into which again a glassring h, Warrying the division of the circle of altitude, isiixed. Vithin the glass ring/t there is a prism system 2', i exactly of the horizontal circle. of the illuminating raypencil is eiiected by means of alreflecting prism 2' inserted The rays em r ing fromthe two illuminated places of the divided circle are again reflected intot'h'e hollow, axial space of the part 9, penetrate a.

intc the hollow journal.

common lenssystem is, representing the ini'-' croscope ob ect1v,c, and then get down with the aid'of a reflecting prism k through the hollow arm of'the telescope carrier a ton corresponding to the disposition of prisms The transmission prism system Z, cemented together of two parts, which retransmits the rays close below the ray pencil systems, emerging from the horizontal circle, approximately parallel to the same. The rays emerging-from the horizontal circle thereby pass through the upper,

v plano-parallel' part oi the prism system Z in the direction of the ra s most plate m and 1m.

in a straight direction. The tour ray pencil systems, now running parallel to each other in approximately the same direction, penetrate behind the prism system Z oneeach of four closely superposed plane-parallel glass plates 227 m m and mr-, which are so cemented in pairs to two stirrups n and n rotatable about two vertical pivots n and n that ii 'itlran opposite rotation of the two sti'rrups n and n about their common journals both the two images of the horizontal circle and those of the circle of altitude suffer a displacement each in opposite directions. cite-st the two medium plano-parallel plates m and m whilst to the second stirrup 91* there are fixed the uppermost and the lower- Thereby, the thick ness of the piano-parallel plates measured is adapted to the amount of the displacement of the image, desired in each particular case. The required opposite but equally large rotation of the two stirrups n and or is effected by two di's'plac'e'able pins 0 which press against cor- I responding extensions n and n of the stirrups. By means of two springs 0 supported by projections of the casing, the extensions n and n are permanently brought into contact with the pins 0. Theunitorm displacement oi the two pins 0 is initiated by a toothed wheel p, rigidly connected to a roughened disc 32 which wheel Simultaneously engages in two toothed wheels 9, equiaxially supported with the pins 0, thereby coupling both to an equally large rotation in the same direction. Each of the two toothed wheels g forms one piece with a bush 9' with the aid of which it is supported within the casing and which is provided with a female thread in which engages the rear part of the pin 0'.

isflattened on one side and slides therewith .along a guide surface 6 of the casing, the pin 0 1S secured against r0 tation so that by rotating the roughened disc p the piano-parallel plates m fl'nf m and m receive in pairs the des red symmetrlcal rotating motion. Behind the system of the piano-parallel plates all four ray pencil systems are deflected upwards by The one stirrup n carries to this 7 By means of a col-' lar 0 fixed to the pin 0 which 'collar' tion with the slight relative inclination of I both ray pencil systems caused by the two reflecting prisms e is so adjusted for each pair oi images, that the exit pupils cover each other as completely as possible. The

rays emerging from the prism system 7 enter the ocular system, consistingot a fixed lens 8, a reflecting p1-1snr.s* ad ustable from outslde wlth the aid of a lever s and two unitorm, fixed eye-lens systems a (vide Fig.

The double disposition of the eye-lens system s in conjunction with the adjustable prism s purposes to permit of also reading with the telescope completely turned over without changing, the position. to be able to read. oii the amount of the displacement of the image caused by the pianoparallel plates m 922?, m and m, the actuatingtoothed wheel 79 is rigidly connected to a plate 10 ,011 which a round glass disc is cemented equiaxially with the toothed wheel 79. The glass disc carries on its cylindrical circt'im'fer'en'ce a graduation p which oermits of directly reading the subuni'ts o the division of the circle. An appertaining pointer is disposed on the "planeparallel part otthe glass-wedge disc r ypro jecting beyond the glass disc 2 The illumination required for the reading of the graduati'onp on thediscp takes place by means 0'1 a reflecting prism p fixed underneath the disc 72' which prism transmits a lateral ray pencil from below through the glass di's'c 7').

Fig; 6 shows the'im'age presented to the observer in the ocular field. of the iield there appears the pair of images oi the circle of altitude, in the middle one that of the horizontal circle, whilst on the right side both reading line and scale for the displacements of the image are to be seen. Thetwo "divisions of th'erii'cle are divided into thirds of a degree. As with each reading the medium is formed by two single Values, of thevalu'esoit division, lying between the corresponding whole numbers of degrees, being "180 apart, one h'alf is to be taken in each case i. e. when counting the whole angle existing between the two corresponding numbers "of degrees each value of division corresponds to an angle of 10.

The scale for the displacement of the image accordingly comprises the range of 10 minutes and permits of directly rea'd;'ng'1n1nutes In order 7 In the left part assumed that a measurement with the hori zontal circle has taken place; the two scaleimages of the horizontal circle are so adjusted by rotating the roughened disc 19 that the divisions ,are exactly facing each other. shows the angular value up to 10 minutes,

with the numbers marked in the figure the value 10 The appertaining fraction is readily indicated by the scale of displacement, in the case illustrated the value 3'47", so that a total reading of 10 53 47 is to be recorded.

I claim:

1. In a theodolite, a divided circle, a reading microscope, optical means for simultaneously imaging two opposite points of the divided circle in the field of said microscope,

relatively movable pairs of planoparallelglass plates, each pair inserted in the path of rays from a respective one of the two images, and means for adjustingthe pairs simultaneously in opposite directions.

2. In a theodolite, a divided circle, a reading microscope, optical means for simultaneously imaging two opposite points of the divided circle in the field of said microscope, relatively movable pairs of plano-parallel glass plates, each pair inserted in the path of rays from a respective one of the two images, resilient means for urging the pairs totheir normal position, and means adjusting the pairs in opposite directions against the ten sion of said resilient means.

3. In a theodolite, a divided circle, a read- About in the centre of each The reading of the chief division ing microscope, optical means for simulta-" neously imaging two opposite points of the divided circle in the field of said microscope, relatively movable pairs of lano-parallel of rays from a respective one of the two images, means for ad usting the pairs on an axis at right angles to the pencil rays of the images, said microscope having branched reading tubes, and means for selectively refleeting the reading to either tube.

4. In a theodolite, a divided circle, a reading microscope, optical means for simultaneously imaging two opposite points of the divided circlein thefield of said microscope, relatively movable pairs of piano-parallel glass plates, each pair inserted in the path of rays from a respective one of the two images, means for adjusting the pairs on an axis at right angles to the pencil rays of the images, said microscope having spaced reading lenses, and an adjustable reflecting prism movable to permit reading from either lens. I

5. A casing having an upstanding journal bearing, a telescope-carrying frame having a hollow pivot journaled in said bearing, a divided circle fixed in the casing, a tubular casing transversely arranged on the lower end of the pivot and within the first casing and securingthe pivot in position, reflecting prisms in the tubular casing within the plane of the divided circle, a reflecting prism in the upper end of the pivot, a microscope, and displacing means between the last prism and the microscope.

HEINRICH WILD.

lVitnesses FRITZ LA NDER, RICHARD HAHN.

glass plates, each pair inserted in the path 

